The key difference between esterase and lipase is that the esterase is an enzyme that hydrolyzes water-soluble short acyl chain esters while the lipase is an enzyme that hydrolyzes water-insoluble long chain triacylglycerols.
Hydrolases are enzymes that catalyze essentially, the hydrolysis of organic compounds. In the field of lipids and fat digestion and hydrolysis, there are two main types of hydrolases involved. They are esterases and lipases. Esterase is an enzyme that catalyzes the hydrolysis of ester compounds. In comparison, lipase belongs to a subset of esterase. It catalyzes the hydrolysis of lipids, especially during the digestion. Esterases are water-soluble substances whereas lipases are water-insoluble and heavily aggregate in water.
CONTENTS
1. Overview and Key Difference
2. What is Esterase
3. What is Lipase
4. Similarities Between Esterase and Lipase
5. Side by Side Comparison – Esterase vs Lipase in Tabular Form
6. Summary
What is Esterase?
Esterase is a type of hydrolase that can cleave and form ester bonds. Therefore, the esterase can cleave the ester bond giving rise to alcohol and acid under aqueous conditions. Especially esterases hydrolyze short-chain fatty acids. They are very stereospecific and substrate-specific enzymes. Moreover, they are mainly involved in catabolic pathways and ultra-purification of isolated lipid compounds. Accordingly, esterases are commonly available in animals, plants and microorganisms. The naming of esterase takes place based on their substrates. For example, acetylcholine esterase will hydrolyze only acetylcholine and not any other substrate.
Figure 01: Esterase
Furthermore, an esterase is water soluble and less soluble in organic solvents. Therefore, esterases have more polar amino acids in their structural organization. Hence, they are inactive against long chain fatty acids such as triacylglycerols. Thus, hydrolysis of long chain fatty acids requires a substitute enzyme such as lipase.
What is Lipase?
Lipase is a water-insoluble lipid hydrolytic enzyme. Hence, lipase forms aggregate in aqueous solutions. It is the most common lipid hydrolytic enzyme in all organisms. In higher level eukaryotes, lipase is available as salivary lipase, abdominal lipase, and intestinal lipase.
Figure 02: Lipase
Moreover, lipases are a subset of esterases. However, in contrast to esterase, lipase is soluble in organic solvents. Therefore, they readily react with large non-polar fatty acid chains and hydrolyze them. Likewise, long-chain triglycerides undergo hydrolysis via lipases. However, the enzyme lipase is more general and is less substrate specific. Furthermore, they contain more hydrophobic amino acids which make them more non-polar in nature.
What are the Similarities Between Esterase and Lipase?
- Esterase and lipase exist in all kingdoms including animals, plants and microorganisms.
- Both have broad substrate specificity.
- Also, both esterase and lipase act upon fatty acids.
- Moreover, both participate in hydrolysis reactions.
- Besides, they are proteins and may or may not have overlapping protein sequences or protein domains.
What is the Difference Between Esterase and Lipase?
Esterase and lipase are two enzymes that are important in lipid hydrolysis and digestion. In fact, lipase is an enzyme that belongs to a subset of esterases. The key difference between esterase and lipase is that the esterase catalyzes the hydrolysis of short-chain fatty acids while the lipase catalyzes the hydrolysis of long chain fatty acids. Furthermore, esterase mainly acts on water-soluble substrates while the lipase mainly acts on water-insoluble substrates. Therefore, this is also a difference between esterase and lipase.
Also, a further difference between esterase and lipase is that the esterase contains less number of hydrophobic amino acids while lipase contains a number of hydrophobic amino acids. Hence, esterases are water soluble while lipases are not soluble in water. Apart from that, esterases show high substrate specificity and high stereospecificity compared to lipases. So, it is another difference between esterase and lipase.
The below infographic on the difference between esterase and lipase shows more information on these differences.
Summary – Esterase vs Lipase
Both esterase and lipase belong to the hydrolase family, and they hydrolyze fatty acids. The key difference between esterase and lipase depends on their solubility and the type of fatty acid they hydrolyze. Esterase is soluble in water. In comparison, lipase is not soluble in water. Moreover, esterase hydrolyzes short-chain fatty acids, whereas lipase hydrolyzes long chain fatty acids. Both enzymes are present in all organisms and are important in the digestion process of lipids. Hence, this is the summary of difference between esterase and lipase.
Reference:
1. Chahinian, H, and L Sarda. “Distinction between Esterases and Lipases: Comparative Biochemical Properties of Sequence-Related Carboxylesterases.” Current Neurology and Neuroscience Reports., U.S. National Library of Medicine. Available here
Image Courtesy:
1.”Enzyme Polyneuridine Aldehyde Esterase”By Mikirehil (CC BY-SA 3.0) via Commons Wikimedia
2.”Pancreatic lipase–colipase complex with inhibitor 1LPB”By Fvasconcellos (Public Domain) via Commons Wikimedia